The vulnerability assessment of power system can select a potential weak link in the system, which is the basic work to prevent and reduce power system blackout. Comprehensive consideration of energy margin and sensitivity is proposed to state the node''s vulnerability index, and vulnerability risk factor is considered to characterize the capability of nodes, and the network topology parameters are considered. Considering the running state, the fault factors and the structural properties of the nodes, the integrated vulnerability assessment model is established. The model overcomes the shortcomings of the traditional vulnerability assessment method. The simulation analysis of IEEE-30 bus system verifies the rationality of the proposed method.